JPH11252362A - Image processor and reference white board dirt discriminating method in the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the abnormality of a shading correction processing owing to the partial dirt on a reference white board and to prevent the generation of defective pixels by discriminating the presence or the absence of the dirt on the reference board, based on the comparison of read data between the reference board and an original. SOLUTION: A read means 1 reads an image from an original 9 at every line and reads a white image for plural times from a reference whiteboard 8 before the reading of the original 9 has started. A correction means 2 mainly corrects the dispersion of output values between the pixels in an optical system and those in the read means 1 with respect to image data which is read by the read means 1, based on read data of the reference whiteboard 8. A reference whiteboard data storage means 3 stores read data of the reference whiteboard 8 for whole pixels. An original data storage means 4 stores read data on the end part of the original 9 for all the pixels. A discriminating means 5 compares the data in the reference whiteboard data storage means 3 with those in the original data storage means 4 for the respective pixels, and discriminates that the reference whiteboard 8 is stained where the difference of both data compared exceeds a prescribed value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus and a reference white board stain determining method in the image processing apparatus. More specifically, the present invention relates to a reference white board for obtaining reference data when performing shading correction. The present invention relates to an image processing apparatus suitable for preventing troubles caused by image processing, and a reference whiteboard stain determination method in the image processing apparatus.

[0002]

2. Description of the Related Art Conventionally, there is a digital copying machine which optically reads an original image by a reading sensor such as a CCD line sensor and records an image based on image data obtained by the reading. In this type of digital copying machine, shading correction processing is performed in order to correct the light amount distribution characteristics of an exposure lamp that irradiates a document, and variations between pixels of a reading sensor (such as a CCD line sensor). The shading correction process is a process of reading data of a reference white plate arranged in a non-image portion on a document table in advance, and correcting image data based on the data.

[0003]

However, the above-mentioned conventional digital copying machine has the following problems. That is, the uniformity of the density of the reference white plate is impaired because the reference white plate accumulates stains due to long-term use, or becomes dirty when the apparatus is once disassembled by exchanging the exposure lamp or the like. There was a case. When the uniformity of the density of the reference white plate is impaired in this way, there is a problem that a high-quality image cannot be obtained because the shading correction is not performed normally.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and enables shading due to partial contamination of a reference white plate by enabling detection when the reference white plate is partially contaminated for some reason. An object of the present invention is to provide an image processing apparatus and a reference whiteboard stain determination method in the image processing apparatus, which can prevent abnormalities in the correction processing and thereby prevent generation of a defective image.

[0005]

According to one aspect of the present invention, there is provided an image processing apparatus having a function of correcting image data based on data read from a reference white plate, wherein the image processing apparatus includes: Reading means for reading, correcting means for correcting the read image data based on the read data of the reference white board, and determining whether or not the reference white board is dirty based on a comparison between the read data of the reference white board and the read data of the document. It is characterized by comprising a determining means and a warning control means for giving a warning when it is determined that the reference white plate is dirty.

In order to achieve the above object, a second aspect of the present invention includes a conversion unit for converting image data obtained by reading a document line by line with the reading unit into digital image data, and the correction unit includes: And a digital correction unit configured to digitally correct a variation in an output value between pixels of the reading unit with respect to the converted image data based on the reading data of the reference white plate.

According to a third aspect of the present invention, there is provided a reference white plate data storage means for storing the read data of the reference white plate for all pixels, and a document data for storing the read data of the document end portion for all pixels. A storage unit, wherein the determination unit compares both data in the two storage units for each pixel, and when there is a pixel in which the difference between the two data exceeds a predetermined value, the reference white board is dirty. And the warning control means:
A warning is issued based on the determination.

According to another aspect of the present invention, there is provided a reference white board data storage means for storing the read data of the reference white board for all pixels, and a document data for storing the read data of the end of the document for all pixels. Storage means, and wherein the determination means determines that the reference white plate is soiled when the number of times the number of pixels in which the difference between the two data in the two storage means exceeds a predetermined value is equal to or greater than a predetermined number. Determining, the warning control means:
A warning is issued based on the determination.

According to another aspect of the present invention, there is provided a reference white plate data storage means for storing the read data of the reference white plate for all pixels, and a document data for storing the read data of the document end portion for all pixels. Storage means, wherein the determination means stores the difference between the two data in the two storage means for a plurality of times and when the location where the difference is large is near the same pixel each time, the reference white board is It is characterized in that it is determined that the device is dirty, and the warning control means issues a warning based on the determination.

In order to achieve the above object, the invention according to claim 6 is characterized in that the warning control means outputs a warning indicating that the reference white plate is dirty from the warning means.

In order to achieve the above object, the invention of claim 7 is characterized in that the warning means is a display means for displaying and outputting a warning indicating that the reference white plate is dirty.

In order to achieve the above object, the invention according to claim 8 is characterized in that the warning means is a sound output means for outputting a warning indicating that the reference white plate is dirty.

In order to achieve the above object, a ninth aspect of the present invention is characterized in that the warning means is a print output means for printing and outputting a warning indicating that the reference white plate is dirty.

In order to achieve the above object, a tenth aspect of the present invention has a copying function.

In order to achieve the above object, an eleventh aspect of the present invention has a printer function.

In order to achieve the above object, a twelfth aspect of the present invention has a facsimile function.

In order to achieve the above object, an invention according to a thirteenth aspect is a reference white board stain determining method in an image processing apparatus having a function of correcting image data based on data read from a reference white board, wherein an image is read from a document. A reading step of reading, a correcting step of correcting the read image data based on the read data of the reference white board, and determining whether the reference white board is dirty based on a comparison between the read data of the reference white board and the read data of the document. The method further includes a determining step and a warning control step of issuing a warning when it is determined that the reference white plate is dirty.

In order to achieve the above object, the invention according to claim 14 has a conversion step of converting image data obtained by reading a document line by line in the reading step into digital image data, The method according to claim 1, further comprising the step of digitally correcting variations in output values between pixels in the reading step in the converted image data based on the read data of the reference white plate.

According to another aspect of the present invention, there is provided a reference white board data storing step of storing read data of the reference white board for all pixels, and a document data for storing read data of a document end portion for all pixels. A storage step, wherein in the determination step, the two data stored in the two storage steps are compared for each pixel, and when there is a pixel in which the difference between the two data exceeds a predetermined value, the reference white board is stained. Is determined, and a warning is issued based on the determination in the warning control step.

In order to achieve the above object, the invention according to claim 16 is a reference white board data storing step of storing the read data of the reference white board for all pixels, and a document data for storing the read data of the document edge for all pixels. And a storage step, wherein in the determination step, when the number of times that there is a pixel in which the difference between the two data stored in the both storage steps exceeds a predetermined value becomes a predetermined number or more, the reference white board becomes dirty. Is determined, and a warning is issued based on the determination in the warning control step.

According to another aspect of the present invention, there is provided a reference whiteboard data storing step of storing the readout data of the reference whiteboard for all pixels, and a document data storing the readout data of the edge of the document for all pixels. Storing the difference between the two data stored in the two storing steps for a plurality of times, and when the location where the difference is large is near the same pixel each time, It is characterized in that it is determined that the white plate is dirty, and in the warning control step, a warning is issued based on the determination.

In order to achieve the above object, the invention of claim 18 is characterized in that in the warning control step, a warning indicating that the reference white plate is dirty is output in the warning step.

In order to achieve the above object, the invention of claim 19 is characterized in that the warning step is a display step of displaying and outputting a warning indicating that the reference white plate is dirty.

In order to achieve the above object, a twentieth aspect of the present invention is characterized in that the warning step is a voice output step of outputting a warning indicating that the reference white board is dirty.

In order to achieve the above object, the invention of claim 21 is characterized in that the warning step is a print output step of printing and outputting a warning indicating that the reference white plate is dirty.

To achieve the above object, the invention of claim 22 is characterized in that it can be applied to an image processing apparatus having a copy function.

In order to achieve the above object, the invention according to claim 23 is characterized in that it can be applied to an image processing apparatus having a printer function.

In order to achieve the above object, the invention of claim 24 is characterized in that it can be applied to an image processing apparatus having a facsimile function.

[0029]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a functional block diagram showing a configuration of a main part of a digital copying machine according to an embodiment of the present invention and corresponding to the claims. A digital copying machine according to an embodiment of the present invention includes a reading unit 1 and a correcting unit 2.
A reference whiteboard data storage unit 3, a document data storage unit 4, a determination unit 5, a warning control unit 6, and a warning unit 7.
And a reference white plate 8.

The function of each section will be described.
Reads an image from the document 9 line by line, and
The white image is read a plurality of times from the reference white plate 8 before the reading of the image is started. The correction unit 2 mainly corrects the variation of the output value between the pixels of the optical system and the reading unit 1 based on the read data of the reference white plate 8 for the image data read by the reading unit 1. The reference white board data storage means 3 stores the read data of the reference white board 8 for all pixels. The document data storage means 4 stores the read data of the edge of the document 9 for all pixels. The determination means 5
The data of the reference whiteboard data storage unit 3 and the data of the original data storage unit 4 are compared for each pixel, and if there is a pixel whose difference between the two data exceeds a predetermined value, it is determined that the reference whiteboard 8 is dirty.

The warning control means 6 controls to give a warning when the determination means 5 determines that the reference white plate 8 is dirty. The warning unit 7 issues a warning based on the control of the warning control unit 6 to indicate that the reference white plate 8 is dirty. in this case,
Examples of the warning unit 7 include a display unit that displays and outputs a warning message, a voice output unit that outputs a warning sound by voice, and a print output unit that prints out a warning message. The reference white plate 8 is provided in a non-image portion on the document table, and performs shading for correcting a variation in output level of an image signal due to uneven sensitivity of the reading unit 1 and uneven light sources and light amounts. This is a reference for obtaining correction data.

The reading means 1 corresponds to a CCD line sensor 401 shown in FIG. 6 described later, and the correcting means 2 corresponds to FIG.
The reference whiteboard data storage means 3 and the original data storage means correspond to a memory 802 in FIG. 20 described later, and the determination means 5 and the warning control means 6 correspond to a CPU 423 in FIG. 6 described later. The display means 7 corresponds to a touch panel 307 of the operation unit in FIG. 5 described later, and the reference white plate 8 is a reference white plate (standard white plate) 26 in FIG.
Corresponds to 0. Further, the solid line in the figure shows the flow of signals between the above-mentioned units, and the broken line in the figure shows the reference white plate 8 by the reading means 1,
The reading of the original 9 is shown.

FIG. 2 is an explanatory diagram showing the internal structure of the digital copying machine according to the embodiment of the present invention. A digital copying machine according to an embodiment of the present invention includes a document placing glass (document table) 200, an exposure lamp 201, first, second, and third mirrors 202, 204, and 205, a lens 207, and a CCD.
Line sensor 208, cooling fan 209, exposure control unit 2
10, developing unit 211, fixing unit 212, fixing unit roller 21
3, cooling roller 214, feeding rollers 215, 217, 2
18, 219, 221, 230, 233, 234, 23
5, paper discharge roller pair 216, separation lever 220, directional flapper 222, transfer paper stacking portions 223, 224, lift-ups 225, 226, cleaner 227, primary charger 22
8, feed roller pairs 229, 231, 232, manual feed tray 237, registration rollers 238, transfer charger 239,
Photoconductor 240, transport belt 241, paper discharge tray 242,
An intermediate tray 243, a static elimination needle 244, first paper detection sensors 250, 251, 252, 253, 254, 255, a standard white plate 260, an operation unit (see FIG. 5), and the like are provided.

The structure of each of the above-mentioned parts will be described in detail together with the operation.
The exposure lamp 201 includes a fluorescent lamp, a halogen lamp, and the like, and irradiates the original on the original placing glass (original table) 200 while moving in the direction perpendicular to the longitudinal direction. The scattered light from the document by the irradiation of the exposure lamp 201 is reflected by the first, second, and third mirrors 202, 204, and 205 and reaches the lens 207. At this time, the exposure lamp 2
01 and first movable body 2 composed of first mirror 202
03, the second movable body 206 composed of the second mirror 204 and the third mirror 205 moves at half speed, and the distance from the irradiated original surface to the lens 207 is It is always kept constant.

The image on the original is transmitted via a first, second, and third mirrors 202, 204, 205 and a lens 207 to a light receiving portion of a CCD line sensor 208 in which thousands of light receiving elements are arranged in a line. The CCD line sensor 208
, The photoelectric conversion is sequentially performed in line units. The photoelectrically converted signal is processed by a signal processing unit (not shown), and is subjected to PWM.
(Pulse Width Modulation) is modulated and output. The exposure control unit 210 drives the semiconductor laser based on the PWM-modulated image signal output from the signal processing unit, and irradiates the surface of the photoconductor 240 rotating at a constant speed with a light beam. At this time, the light beam is deflected and scanned using a polygon mirror in parallel with the axial direction of the drum-shaped photoconductor 240. The exposure control unit 210 is cooled by the cooling fan 209.

Before the light beam is irradiated, the remaining charge on the drum of the photosensitive member 240 is removed by a pre-exposure lamp (not shown), and the surface of the photosensitive member 240 is uniformly charged by a primary charger 228. Have been. Therefore, the photosensitive member 240 receives the light beam while rotating, so that an electrostatic latent image is formed on the drum surface. Then, the electrostatic latent image on the drum surface is visualized by the developing device 211 with a developer (toner) of a predetermined color.

On the other hand, in the transfer paper stacking sections 223 and 224, fixed-size transfer papers are stacked and stored. The lift-ups 225 and 226 are provided in the transfer paper stacking units 223 and 224.
The transfer paper stored in the feeding roller pair 229, 23
An operation of lifting to the position 2 is performed. Feeding roller pair 22
9 and 232 are driven by the same motor (not shown), and the transfer paper stacking unit 2 is switched by switching the roller rotation direction.
The paper to be transferred is selectively fed from one of 23 and 224. In addition, a torque is applied to each pair of the feeding roller pairs 229 and 232 in a direction opposite to the paper feeding direction, thereby preventing double feeding of the recording medium (transferred paper).

Feed rollers 230, 233, 234, 23
5 feeds the transfer sheet from the transfer sheet stacking units 223 and 224 to the registration roller 238. In the present embodiment, it is possible to extend the third and fourth receiving paper stacking portions further downwardly with respect to the above-described receiving paper stacking portions 223 and 224. The feed roller pair 231 performs a feed operation in which the transfer paper is guided by the feed roller from the transfer paper stacking portion connected below. When the manual paper feed mode is selected on the operation unit, the manual feed tray 237 is opened and the paper to be transferred is manually fed, and the feed roller 236 feeds the manually fed paper to the registration roller 238. I do.

The registration roller 238 feeds the transferred paper to the transfer position by adjusting the timing of the leading end of the image formed on the photosensitive member 240 and the leading end of the transferred paper. Transfer charger 2
Reference numeral 39 transfers the developed toner image on the photoconductor 240 to the fed paper. After the transfer, the residual toner is removed from the photoconductor 240 by the cleaner 227. The transferred paper on which the transfer has been completed is easily separated from the photoconductor 240 because of the large curvature of the photoconductor 240. However, by applying a voltage to the static elimination needle 244, the attraction force between the photoconductor 240 and the transferred paper is further increased. To make separation easier.

The separated transfer paper is transferred to a transport belt 241.
Is sent to the fixing unit 212 and the fixing unit roller 213 to fix the toner. The fixing unit 212 includes, for example, a ceramic heater, a film, and two rollers, and heat of the ceramic heater is efficiently transmitted through a thin film. The cooling roller 214 radiates heat from the fixing roller 213. The feed roller 215 includes one large roller and two small rollers, feeds the paper to be transferred from the fixing unit 212 and the fixing unit roller 213, and corrects the curl of the paper to be transferred. The direction flapper 222 switches the transport direction of the transfer sheet according to the operation mode. In a mode in which the transfer is performed once to one side of the receiving sheet (during single-side recording), a path from the feed roller 215 to the sheet discharge port is selected. The discharge roller pair 216 stacks and discharges the transfer-receiving paper on which the image formation has been completed on the discharge tray 242.

During double-sided recording, the discharge roller pair 216 is rotated in the reverse direction while the rear end of the transfer paper is left during the discharge operation of the discharge roller pair 216 after the development of one side of the transfer paper is completed. Let it. At the same time, the direction of the directional flapper 222 is switched so that the transfer target paper passes under the directional flapper 222,
The paper to be transferred is sent from the paper outlet to the feed roller 217. The feed roller 217 has the same configuration as the feed roller 215, corrects the curl of the transfer sheet, and sends the transfer sheet to the intermediate tray 243. Thereafter, the transfer paper is transferred to the intermediate tray 24.
3, the paper is fed to the above-described transfer position in the order of the feed rollers 218, 219, 221 and 235, the toner is transferred to the back surface of the transfer paper, and further discharged to the discharge tray 242.

Also, at the time of multiplex recording, the transferred paper passing through the feed roller 215 passes through the right side of the directional flapper 222 on the paper surface of FIG. Sent to Feed roller 2
17 sends the transfer paper to the intermediate tray 243. afterwards,
The transfer paper is fed from the intermediate tray 243 to the feeding roller 218,
The paper is fed to the above-described transfer position in the order of 219, 221, and 235, the toner is transferred to the same surface as the previous transfer, and further discharged to the paper discharge tray 242.

When recording a plurality of sheets during double-sided printing or multiplex printing, the first sheet to be transferred is stacked on the intermediate tray 243 while being fixed by the stopped feeding roller 218. When the second transfer sheet arrives, the feed roller 218 starts rotating, and sandwiches the two transfer sheets between the rollers. The two transfer sheets are stacked on the intermediate tray 243 while being fixed by the stopped feeding roller 218. The third and subsequent sheets to be transferred are also stacked on the intermediate tray 243 in the same manner. At this time, the leading end of the transferred paper
As shown in FIG. 3, the sheets are superimposed so as to be shifted rearward with respect to the feeding direction.

When the desired number of sheets to be transferred are stacked on the intermediate tray 243, the feeding operation from the intermediate tray 243 starts. While the feed rollers 218 and 219 are feeding the transfer sheet to the feed roller 221, the separation lever 220
The sheet is lowered between the leading ends of the first and second transfer sheets, and the first transfer sheet is sent to the feed roller 221 as it is, fed by the feed roller 235, and guided to the transfer position. Transfer is performed. Further, after the second and subsequent sheets are transferred on the separation lever 220, the transfer rollers 218, 219
Is rotated backward and returned to the intermediate tray 243. The same operation is repeated to feed all the sheets to be transferred from the intermediate tray 243.

The first to sixth paper detection sensors 250 to 2
Reference numeral 55 is disposed in the transfer path of the transfer sheet, and is used for detecting an error such as a paper jam and measuring the operation timing of each unit. The first paper detection sensor 250 is connected to the feeding roller 23.
5, the second paper detection sensor 251 is before the registration roller 238, the third paper detection sensor 252 is before the feed roller 215, and the fourth paper detection sensor 253 is a paper discharge roller pair 216 and a paper discharge port. During the period, the fifth paper detection sensor 254 is disposed immediately after the feed roller 217, and the sixth paper detection sensor 255 is disposed before the separation lever 220.

The standard white plate (reference white plate) 260 is a CCD
This is for obtaining shading correction data for correcting a variation (shading distortion) of an output level of an image signal due to unevenness of sensitivity of the line sensor 208, unevenness of a light source and light amount, and the like. Platen)
It is arranged in a non-image part on the image 200. Prior to scanning of the original, the standard white plate 260 is scanned a plurality of times by the CCD line sensor 208, and the white image data obtained thereby is used as shading correction data, and the original image is scanned by the CCD line sensor 208 to obtain an image. The signal level non-uniformity correction (shading correction) is performed.

FIG. 4 is a sectional view showing an internal structure of an automatic document feeder (hereinafter, ADF) of a digital copying machine according to an embodiment of the present invention. The ADF has a side regulating member 15.
01, roller holders 1502, 1504, paper feed roller 1
503, separation roller 1505, lever switch 150
6, 1507, 1513, registration roller pair 1508,
1509, original holder 1510, discharge roller pair 151
1, 1512, a paper discharge tray 1514, a document stacking tray 1517, a lever 1518, a stopper 1519, and the like. The ADF is configured to be detachable from the main body of the digital copying machine, and has a lid-like structure that can be opened and closed with respect to the document table. FIG. 4 shows a state in which the ADF is closed. At this time, the ADF is operable.

The configuration of each of the above-described units together with the operation will be described in detail.
The document table glass 1515 corresponds to the document table glass (document table) 200 of the main body of the digital copying machine shown in FIG. The attachment plate 1516 is a member belonging to the digital copying machine main body side. Further, the ADF and the digital copying machine main body are electrically connected via a cable (not shown) so that the ADF and the digital copying machine main body can be operated jointly with the digital copying machine main body. The side regulating member 1501 is configured to be movable in a direction perpendicular to the document feeding direction, that is, in the front and back directions on the paper surface of FIG. 4, and to adjust the width and the position of the document. When the operator places a document on the document stacking tray unit 1517 with the document face down, sets the side regulating member 1501, operates the copy start key 305 (see FIG. 5), and starts a copy operation or the like. A feed start signal is transmitted from the main body of the digital copying machine via the cable, and the original feeding operation starts.

When feeding paper, the lever 1518 pushes down the roller presser 1502 to lift the stopper 1519 upward, and feeds paper by rotation of the paper feed roller 1503. The separation roller 1505 and the roller presser 1504 separate and feed the originals received from the paper feed roller 1503 one by one. The registration roller pair 1508 and 1509 are connected to the separation roller 150.
5 is sent between the original holder 1510 and the original platen glass 1515. The document holder 1510 has a shape in which a document fed from the pair of registration rollers 1508 and 1509 is guided onto the document table glass 1515. Further, the original is appropriately pressed by a spring member (not shown) so that the original comes into close contact with the original platen glass 1515.

At this time, the first movable body 203 (see FIG. 2) of the digital copying machine
It has moved below the position 1520 in close contact with 515 and stopped. Thus, the original sent by the ADF is scanned (photoelectric conversion is performed by the CCD line sensor 208). The discharge roller pairs 1511 and 1512 discharge the scanned document onto a discharge tray 1514. still,
Lever switches 1506, 1507, and 1513 detect the passing state of the document during the document feeding operation.
An error such as a paper jam is determined at the timing of N / OFF.

FIG. 5 is an explanatory diagram showing the key arrangement of the operation unit of the digital copying machine according to the embodiment of the present invention. The operation unit includes a preheat key 301, an option mode key 302,
Fax mode key 303, copy mode key 30
4. Copy start key 305, stop key 306,
Touch panel 307, reset key 308, guide key 309, user mode key 310, interrupt key 31
1, numeric keypad 312, clear key 313, one touch
Dial key 314, main power lamp 315, lid 31
6. Equipped with status display lamps 317-322.

The configuration of each of the above-described units together with functions will be described in detail.
The main power lamp 315 lights up when the power is turned on. A power switch (not shown) is arranged on the side of the digital copier main body, and controls the power supply to the main body. Preheating key 30
1 is used for ON / OFF of the preheating mode. The copy mode key 304 is used to select a copy mode from a plurality of functions. Fax mode key 303
Is used to select the fax mode from multiple functions. An option mode key 302 is used to select an option mode from a plurality of functions when an option such as a printer is mounted on the digital copying machine.

The status display lamps 317 and 318 indicate the status during the copying operation, and the status display lamps 319 and 320
Indicates a status during facsimile operation, and a status display lamp 3
Reference numerals 21 and 322 indicate states during the option operation. The status display lamps 317, 319, and 321 indicate a normal operation state, and the status display lamps 318, 320, and 322.
Indicates an error condition. Further, if the status display lamp 317 blinks, it indicates that copying is being performed, and if it is lit, it indicates that the image memory is being used. If the status display lamp 319 is blinking, it indicates that fax transmission / reception is being performed, and if it is lit, it indicates that the image memory is being used. If the status display lamp 321 blinks, it indicates that data is being received, and if it is lit, it indicates that data is being transmitted. If the status display lamps 318, 320, and 322 blink in each mode, they indicate a paper jam, no paper, and no toner, and if lit, indicate a failure.

A copy start key 305 is a key used to instruct the start of copying. Stop key 3
A key 06 is used to interrupt or stop copying. The reset key 308 operates as a key for returning to the standard mode during standby. The guide key 309 is a key used when it is necessary to know each function. The interrupt key 311 is used when the user wants to interrupt the copying and perform the copying. The ten keys 312 are used to input numerical values. The clear key 313 is used to clear a numerical value. User mode key 310
Is used by the user to change the basic settings of the system.

The one-touch dial key 314 is composed of, for example, 20 keys, and is used for one-touch dialing in facsimile transmission. The lid 316 is configured as a two-sheet set, and is a double lid having a shape in which each key portion of the one-touch dial key 314 is hollowed out. A sensor switch (not shown) detects a first state in which the two lids are closed, a second state in which only the first lid is open, and a third state in which the two lids are open. One-touch dial key 314 in combination with the open / closed state of these three types of lids
In this embodiment, there is an effect equivalent to the case where there are 20 × 3 = 60 keys.
The touch panel 307 is a panel composed of a combination of a liquid crystal screen and a touch sensor. An individual setting screen is displayed for each mode, and various detailed settings can be made by touching drawn keys. is there.

FIG. 6 is a block diagram showing the configuration of the signal processing system of the digital copying machine according to the embodiment of the present invention.
The signal processing system of the digital copying machine includes a CCD line sensor 401, an A / D conversion unit 402, a shading correction unit 4
03, pattern generator 404, selector A / 40
5, connector A 406, selector B 407, scaling unit 408, SRAM (Static RAM) memory A4
09, a filter processing unit 410, a line buffer 411,
Image processing unit 412, connector B 413, selector C
414, connector C / 415, synthesis processing unit 416, table conversion processing unit 417, SRAM memory B / 418, 2
Value processing section 419, buffer 420, PWM circuit 42
1, laser unit 422, CPU 423, timing signal generation unit 424, control signal generation unit 425, operation unit 426, A
It comprises a DF 427 and a polygon driver 428.

The structure of each of the above components will be described in detail. The CCD line sensor 401 (the CCD line sensor 208 shown in FIG.
Is composed of thousands of light receiving elements, and 1
The electric signals for the lines are divided and output into two systems of odd-numbered pixels and even-numbered pixels. The A / D converter 402 receives an analog signal output from the CCD line sensor 401, converts the analog signal into a digital signal, and outputs the digital signal. Shading correction unit 4
Numeral 03 inputs an A / D-converted digital signal, and digitally corrects mainly the variation in the output value between the optical system and the pixels of the CCD line sensor 401 with respect to the black level and the gain. The pattern generator 404 generates various image patterns such as a vertical ruled line, a horizontal ruled line, a lattice pattern, a gray scale, and the like, for checking functions after the scanner unit.

The selector A 405 selects and outputs one of the outputs of the shading correction unit 403 or the pattern generator 404 according to a control signal of the CPU 423. The connector A 406 has terminals for an image input signal, an image output signal, a pixel clock signal, an image enable signal, and a synchronization signal. The output of the selector A 405 is connected to the terminal of the image output signal, and the function can be expanded by connecting a new signal processing circuit to the connector A 406. Selector B / 407 is connected to connector A / 40
6 enables expansion of functions. The selector B / 407 outputs one of the output signal from the selector A / 405 and the output signal from the connector A / 406 to C
It selects and outputs according to the control signal of PU423.

The scaling unit 408 has functions of thinning processing in the main scanning direction, linear interpolation processing, thinning processing in the sub-scanning direction, italic processing, mirror image processing, repeat processing, and return processing. Zooming in the main scanning direction is realized by inputting a signal from the selector B 407 and calculating a pixel value from two adjacent pixels by linear interpolation processing. However, when the magnification in the main scanning direction is 50% or less, the main scanning direction thinning process is performed as a pre-process in order to prevent moiré and interruption of fine lines. In the preprocessing, (a) the maximum value or (b) the average value is output for the adjacent n pixels (n = 2, 4, 8). CPU 423 selects the value of n and the processing (a) or (b).
It is implemented by.

The magnification in the sub-scanning direction can be changed by changing the scanning speed of an optical system such as an exposure lamp or a mirror, or by changing the speed of paper feeding to the document table 200 when using an automatic document feeder (ADF). To achieve zooming. However, in the case of a small scaling factor that exceeds the limit of the scanning speed of the optical system or the speeding up of the paper feeding speed, the scaling is performed together with the electrical thinning process in the sub-scanning direction of the scaling processing unit 408. Realize.
In the thinning process in the sub-scanning direction, the SRAM memory A
9 and outputs a (a) maximum value or (b) an average value for n pixels (n = 2, 4, 8) adjacent between lines. value of n and processing (a),
The selection of (b) is performed by the CPU 423. Also,
Each function of the italic processing, the mirror image processing, the repeat processing, and the return processing is realized by reading control of a line buffer including the SRAM memories A and 409.

The histogram is created by selecting the selector B 407
Of the SRAM memory A of the scaling unit 408
Create a histogram using 409. A signal for determining a sampling interval and a sampling range in creating a histogram is controlled by a timing signal generator 424. The timing signal generation unit 424 is
23. The created histogram data is used for determining a table for luminance / density conversion in the AE mode at the time of using the prescan.

The filter processing unit 410 has a line buffer 411, receives the signal after the scaling process, and performs a filter process with a mask size of 5 × 5. As shown in FIG. 9, there are six types of coefficients constituting the filter of the filter processing unit 410, a to f, and the coefficients at point-symmetric positions are set to the same value. A to f have the following relational expressions.

A + 4 * (b + c + d + f) + 8 * e = 1 By adjusting the coefficients of the filter processing unit 410, correction of the optical system and output system and adjustment of sharpness by the user are realized.

The image processing section 412 includes the filter processing section 41
A signal of 0 is input and a masking process or an inversion process is performed. The connector B 413 has terminals for an image input signal, an image output signal, a pixel clock signal, an image enable signal, and a synchronization signal. The output of the filter processing unit 410 is connected to the terminal of the image output signal, and the function can be extended by connecting a new signal processing circuit to the connector B 413. The selector C 414 selects and outputs one of the output signal from the image processing unit 412 and the output signal from the connector B 413 in accordance with the control signal of the CPU 423. The connector C / 415 has an image input signal,
Each terminal has an image output signal, a pixel clock signal, an image enable signal, a synchronization signal, an address bus, a data bus, and an interrupt signal. The output of the selector C / 414 is connected to the terminal of the image output signal, and the function can be expanded by connecting a new system to the connector C / 415. The combining processing unit 416 includes a selector C · 4
14 is input to one input A, and the connector C
The output signal from 415 is input to the other input B, and is synthesized and output. The output types are (1) inset synthesis,
(2) multiple synthesis, (3) halftone overlay, (4) watermark synthesis,
(5) Through input A, (6) Through input B,
It is selected by a control signal of the CPU 423.

Here, each combination will be described with reference to FIG. Inset synthesis is a process in which a part of an image is extracted and inserted into another image, and (d) is an example of this process. An image obtained by extracting a rectangular area around the rectangle of (b) and inserting it into (a) is used. is there. Multiple synthesis is a process of selecting and combining the two images having higher densities, and (e) is an example of this, and is an image synthesized from (a) and (b). In the watermark synthesis, pixels in which the density of one image is equal to or less than a predetermined threshold value are replaced with the other image. At this time, the image to be replaced is multiplied by a predetermined coefficient to reduce the density, and has an effect like a watermark. (F) is an example of this, in which the image of (b) is combined with the watermark of (a). The halftone overlay replaces pixels in one image whose density is equal to or greater than a predetermined threshold with the other image. (G) is an example,
The dark circle in the image of FIG. 7A is replaced by the pattern of FIG.

The table conversion processing unit 417 receives the output signal of the synthesis processing unit 416, performs a table conversion process in accordance with the data of the connected SRAM memory B 418, and outputs the result. The binarization processing unit 419 includes the table conversion processing unit 4
An output signal of the CPU 17 is input, and a selection is made according to a control signal of the CPU 423 to select whether to process the signal by a predetermined binarization method or to output the signal through. In the binarization of the present embodiment, one pixel is divided into two in the main scanning direction, and the divided small pixels are represented by binary values, thereby improving the resolution in the main scanning direction. The buffer 420 receives the output signal of the binarization processing unit 419, and adjusts the processing speed before and after the buffer 420 and the read start time of the image signal.

The PWM circuit 421 receives the digital signal from the buffer 420, performs pulse width modulation, and outputs the result. The PWM circuit 421 has the following three types of first modulation scheme, second modulation scheme, and third modulation scheme, and the CPU 423 determines an appropriate modulation scheme according to the mode of the system. The process is selected and performed.

The first modulation method is a resolution priority mode. As shown in FIG. 11, the pixel data represented by 8 bits is D / A converted, sampled and held, and is converted to a triangular wave signal of one pixel cycle. Rate and output PWM.

The second modulation method is a gradation priority mode. As shown in FIG. 12, pixel data represented by 8 bits is D / A converted, sampled and held, and a triangular wave signal having a period of 3 pixels is output. Comparing and PWM output. still,
FIG. 15 shows a modulation method in which both the sample-and-hold period and the triangular wave signal have a period of three pixels. A low-frequency modulation signal is obtained, and a stable gradation characteristic is obtained. In the second modulation method, the same characteristics as those in FIG. 15 can be obtained for low-frequency image data. However, as shown in FIG. It also has the feature to do.

The third modulation method is a binary image mode, and outputs a binary modulation signal obtained by dividing one pixel into four in the main scanning direction as shown in FIG. The values of the subdivided sub-pixels are the rising and falling of the first pixel clock,
Then, using the rising and falling edges of the second pixel clock obtained by delaying the first pixel clock by 1/4 phase, the respective bits 7, 5, 6, and 4 of the pixel data are latched and obtained. In the binarization method of this embodiment, one small pixel is formed by combining bits 7 and 6 and bits 5 and 4 respectively, and one pixel is used in a form divided into two in the main scanning direction.

The laser section 422 receives the output of the PWM circuit 421 and controls the laser lighting operation. The timing generator 424 and the control signal generator 425 are set by the CPU 423 before the start of the scanner operation. The timing generator 424 generates a timing signal for each part of the system. The control signal generation unit 425 includes a CPU
It operates as an extension port 423 and is used as a control signal for each part of the system. A system address bus and a system data bus, which are buses of the CPU 423, are connected to the respective connectors.
Control the system connected to the connector.

The operation unit 426 corresponds to the operation unit shown in FIG. The CPU 423 also controls key input and display on the operation unit 426. The ADF 427 corresponds to the ADF shown in FIG. The polygon driver 428 drives a polygon mirror (not shown). C
The PU 423 controls the ADF 427 and controls the driving of the polygon driver 428. Further, the CPU 423 controls the execution of the reference white board dirt detection process shown in the flowcharts of FIGS. 21 and 22 described later based on a predetermined control program.

FIG. 7 is a block diagram showing a detailed configuration of the A / D converter 402 of the signal processing system of the digital copying machine according to the embodiment of the present invention. The A / D converter 402 includes an analog processing circuit 901, an A / D converter 902, an analog switch 903, and an AE circuit 904.

The structure of each part will be described in detail. The analog processing circuit 901 includes a CCD line sensor 401 (see FIG. 6).
2), and after clamping, gain adjustment, and sample-and-hold are performed for each system, the signals are integrated into one system by switching processing and output. The A / D converter 902 inputs the output signal of the analog processing circuit 901 to the signal input,
An 8-bit digital signal is output based on the voltage of the reference voltage input from. The AE circuit 904 controls the reference voltage of the A / D converter 902, and controls the A / D converter
An operation of bringing the D converter output closer to the white level (FFhex) is performed.

The analog switch 903 selects one of the constant reference voltage from the analog processing circuit 901 and the reference voltage from the AE circuit 904 according to a control signal from the CPU 423, and outputs the selected voltage to the A / D converter 902. A
The / D conversion section 402 is provided with a drive signal generation circuit (not shown).
A line unit signal such as a synchronization signal and a drive clock are supplied to the analog processing circuit 901 and the A / D converter 902.

Further, the AE circuit 904 includes the A / D converter 9
The reference voltage value of the A / D converter 902 is controlled based on the output of the A / D converter 02. That is, if the output of the A / D converter 902 is FFhex, the AE circuit 904 determines whether the first capacitor and the first resistor connected to the AE circuit 904 (these are not shown).
The reference voltage output is increased as shown in FIG. Also, the A / D converter 9
02 is not an FF hex, the reference voltage is set according to a second time constant determined by a second capacitor and a second resistor (not shown) connected to the AE circuit 904 as shown in FIG. Decrease output. Each of the above time constants is set to several tens of lines so that the reference voltage output does not suddenly change due to a change in the image signal.

FIG. 16 is a block diagram showing the configuration of a system in which a facsimile function, a printer function, and an electronic sorter function are added to the basic copy function of the digital copying machine according to the embodiment of the present invention. A system in which a facsimile function, a printer function, and an electronic sorter function are added to the basic copy function of a digital copying machine includes a signal processing unit 501, a resolution / gradation number conversion unit 502, a facsimile unit 503, an image storage unit 504, and a printer unit 505. It has.

The configuration of each unit will be described in detail. The signal processing unit 501 performs the processing related to the basic copy function shown in FIG. The facsimile unit 503 performs processing related to the facsimile function. The printer unit 505 includes:
Performs processing related to the printer function. Image storage unit 50
4 performs processing related to the electronic sorter function. The image storage unit 504 further has an external connector, and can add functions such as an external scanner and an electronic file.

Since the resolution and the number of gradations are different for each function, the resolution / gradation number conversion unit 502 performs the operation of matching the resolution and the number of gradations between the functions and converting the function to the optimum image quality. This resolution / gradation number conversion unit 502 is connected to the signal processing unit 50.
By connecting to 1, the system can be expanded as needed. The connection between the signal processing unit 501 and the resolution / gradation number conversion unit 502 is made by the connector C in FIG.
415.

The connectors for connecting the resolution / gradation number conversion unit 502 and the signal processing unit 501, the facsimile unit 503, the image storage unit 504, and the printer unit 505 have system address buses, data buses, synchronization signals, Terminals for a pixel clock signal, an interrupt signal, and the like are included. Of these, the address bus and the data bus correspond to the CPs in FIG.
This is a U423 bus. The synchronization signal is generated from the timing generator 424. The pixel clock signal is
It is generated from an oscillator (not shown) of the signal processing unit 501. The interrupt signal is sent to the facsimile unit 503 and the image storage unit 50.
4 and a request for processing from the printer unit 505 or the end of processing,
It is prepared for transmitting the occurrence of an error or the like to the CPU 423 in FIG.

FIG. 17 is a block diagram showing a configuration of a system in which a facsimile function is added to a basic copy function of a digital copying machine according to an embodiment of the present invention. A system in which a facsimile function is added to a basic copy function of a digital copying machine includes a signal processing unit 501, a resolution / gradation number conversion unit 502, and a facsimile unit 503. The configuration of each unit shown in FIG. 17 is the same as the configuration of each unit shown in FIG.

FIG. 18 shows a detailed internal structure of the resolution / gradation number conversion unit 502 in a system in which a facsimile function, a printer function, and an electronic sorter function are added to the basic copy function of the digital copying machine according to the embodiment of the present invention. FIG. The resolution / gradation number conversion unit 502 includes a multiplexer A 601 and a contour smoothing processing unit A
2, table conversion processing unit 603, binarization processing unit 604,
An outline smoothing processing unit B 605, a scaling processing unit 606, and a multiplexer B 607 are provided.

The structure of each part will be described in detail together with the operation.
Multiplexer A 601 has input terminals 1, 2, 3, 4
And output terminals A, B, C, and D, and receives output signals from a signal processing unit 501, a facsimile unit 503, a printer unit 505, and an image storage unit 504 (see FIG. 16 described above). The signal is distributed to the second, third, and fourth signal paths.

The first signal path is a through path.
The second signal path is a path that receives the binary image signal, performs processing for making the contour of the curve look smooth, and outputs the processed signal. The contour smoothing processing unit A 602 uses the multiplexer A 601.
, And receives one pixel for four pixels in the main scanning direction.
One bit is assigned to each of the divided small pixels,
Output with 4 bits per pixel.

The third signal path is a path for binarizing the multi-level signal. The table conversion processing unit 603 receives the multi-level signal from the multiplexer A 601 and converts it into a table. Receives the output signal of the table conversion processing unit 603 and performs binarization processing using the average density method. At this time, one bit is assigned to each of the small pixels obtained by dividing one pixel into two in the main scanning direction, and two bits are output per pixel.

The fourth signal path receives the binary images of various resolutions and performs processing to make the contour of the curve look smooth.
This is a path for outputting a multi-valued bit. The contour smoothing processing unit B 605 receives the binary signal from the multiplexer A 601 and performs processing for making the contour of the curve look smooth, thereby forming an 8-bit multi-valued signal. Then, the scaling unit 606 receives the multi-level output of the contour smoothing processing unit B 605 and performs linear interpolation to output an 8-bit multi-level signal.

The multiplexer B 607 has input terminals 1, 2, 3, and 4 and output terminals A, B, C, and D, and the first, second, third, and fourth signal paths described above. Signal processing unit 501, facsimile unit 50
3, printer unit 505, image storage unit 504 (see FIG.
See).

In the facsimile transmission operation, the image signal is sent from the signal processing unit 501 to the facsimile unit 503 via the resolution / gradation number conversion unit 502. At this time, FIG.
..> C, the image signal passes through the third signal path, and the multiplexers B ・ 607 select C so that 3...> D is selected.
The PU 423 controls. In a facsimile transmission operation, an image signal is sent from the facsimile unit 503 to the signal processing unit 501 via the resolution / gradation number conversion unit 502. At this time, the multiplexer A 601 in FIG.
...> D are selected, the image signal passes through the fourth signal path, and the CPU 423 controls the multiplexer B · 607 so that 4.

In the printer operation, the printer unit 505
The image signal is sent to the signal processing unit 501 through the resolution / gradation number conversion unit 502. At this time, 2...> B is selected for the multiplexers A and 601 in FIG. 18, the image signal passes through the second signal path, and the multiplexers B and 60
7 is controlled by the CPU 423 so that 2...> A is selected. Also, in the printer operation, when performing fixed-size scaling to a different paper size, the image signal is transmitted to the printer unit 5.
05 to the signal processing unit 501 via the resolution / gradation number conversion unit 502. At this time, the multiplexer A · 601 in FIG. 18 selects 2...> D, the image signal passes through the fourth signal path, and the multiplexer B · 607
The CPU 423 controls so that 4...> A is selected.

When the electronic sorter function or the like is used, an image signal is sent from the signal processing unit 501 to the image storage unit 504 via the resolution / gradation number conversion unit 502. At this time, the multiplexer A 601 in FIG. 18 selects 1...> A, the image signal passes through the first signal path, and the multiplexer B
The CPU 607 determines that 1...> C is selected.
3 controls.

In the printer function, when image data is sorted and output in the reverse order, the image signal is once sent from the printer unit 505 to the image storage unit 504 via the resolution / gradation number conversion unit 502. At this time, the multiplexer A 601 in FIG. 18 selects 1...> A, the image signal passes through the first signal path, and the multiplexer B 607
Is controlled by the CPU 423 so that 1 ...> C is selected. The image storage unit 504 writes an image to a hard disk (not shown) and reads the image in the reverse order. The read image signal is sent from the image storage unit 504 to the signal processing unit 501 via the resolution / gradation number conversion unit 502. At this time, the multiplexer A 601 in FIG.
..> B is selected, the image signal passes through the second signal path, and the multiplexer B
The CPU 423 controls so that A is selected.

FIG. 19 shows a facsimile unit 503 in a system in which a facsimile function, a printer function, and an electronic sorter function (or a facsimile function is added to the basic copy function) to the basic copy function of the digital copying machine according to the embodiment of the present invention. FIG. 3 is a block diagram showing a detailed configuration of the embodiment.
The facsimile unit 503 includes a connector C 701, an encode / decode processing unit 702, and a memory control unit 7
03, image memory 704, code memory 705, backup power supply 706, speaker unit 707, NCU unit 70
8, an external connector 709, a modem unit 710, a voice synthesizing unit 711, and a connector D / 712.

The structure of each part described above will be described together with the operation.
The connector C 701 includes terminals for a system address bus, data bus, video input signal, video output signal, synchronization signal, pixel clock signal, interrupt signal, and the like. The facsimile unit 5 is connected to the connector C / 701.
03 and the resolution / gradation number conversion unit 502 are connected.

In the facsimile transmission operation, the memory control unit 703 receives a video input signal from the connector C 701 and stores image data in the image memory 704. The encode / decode processing unit 702 is connected to the memory control unit 703 via an image address bus and a data bus. The encoding / decoding processing unit 702 includes a DMA (Direct Memory Acceses).
s) A controller is built-in, and the communication with the memory control unit 703 allows the
A: High-speed image data is fetched by A transfer, the fetched image data is encoded, and the coded code is DMA
The data is stored in the code memory 705 by transfer. The code memory 705 is provided with a data protection measure by a backup power supply 706 in order to cope with a power supply trouble such as a power failure.

An encoding / decoding processing unit 702, a memory control unit 703, a modem unit 710, and a voice synthesizing unit 711 connected to an address bus and a data bus of the system are connected to a CPU 423 connected via a connector C 701. Is controlled by When the encoding of the image in the image memory 704 ends, the encode / decode processing unit 702 generates an interrupt signal to the CPU 423 notifying the end. CPU receiving the interrupt signal
423 reads the encoded code from the code memory 705 via the memory control unit 703,
The data is written to the modem unit 710 as transmission data.

The transmission data is modulated into an analog signal by the modem section 710 and transmitted from the external connector 709 via the NCU (network control unit) section 708. The speaker unit 707 is connected to the modem unit 710, and can monitor the communication state of the modem unit 710 by voice.

In the facsimile receiving operation, the analog signal received from the external connector 709 is transmitted to the NCU 7
When the modem unit 710 receives the data via the command line 08, it generates an interrupt signal to the CPU 423 notifying the data reception.
Upon receiving the interrupt signal, the CPU 423 sets the
The data is read from 0 and the memory control unit 703 is read.
The code is written to the code memory 705 via the. CPU
When the writing to the encoding memory 705 ends, the 423 sends a write end signal to the encoding / decoding processing unit 702 via the system bus.

The encode / decode processing unit 702 fetches data at high speed by DMA transfer from the code memory 705 by communication with the memory control unit 703, decodes the fetched code data, and DMA-decodes the decoded image data. In the image memory 704. When the decoding of the code in the code memory 705 is completed, the encode / decode processing unit 702 generates an interrupt signal to the CPU 423 notifying the end.

The memory control unit 703 outputs a video signal from the image memory 704 to the connector C 701 according to the timing signal from the connector C 701. Further, the memory control unit 703 uses the internal buffer to shift the image 90 degrees on the image memory 704,
It has a function of rotating at 80 degrees and 270 degrees, and rotates and outputs a received image or a transmitted image as necessary. The voice synthesizing unit 711 synthesizes a voice response message upon receiving an incoming call based on the data set via the system bus, and transmits the message via the NCU unit 708. The connector D / 712 connects the system bus and the image bus, and prepares for expansion of the system for adding lines and improving performance.

FIG. 20 is a block diagram showing a schematic internal configuration of shading correction section 403 (see FIG. 6) in the signal processing system of the digital copying machine according to the embodiment of the present invention. The shading correction unit 403 includes a shading correction operation circuit 801, a memory 802, an addition / averaging circuit 803, an address counter 804, and a selector 805.
It has.

The configuration of each section will be described in detail. The shading correction operation circuit 801 is a block which performs an operation using image input data and data of a reference white board (see FIG. 2) to obtain output image data. The arithmetic expression here is as follows.

Vout = (C * Vin) / D Vout; output image data C; constant Vin; input image data D; data of reference whiteboard Memory 802 stores input image data. The storage capacity of the memory 802 is a capacity capable of storing one line of image data. In addition, the data width (the number of bits) is set to 11 bits in this embodiment in order to allow the input image data (8 bits) to be added eight times in anticipation of adding image data for a plurality of lines. In the memory 802, DO indicates stored data output, DI indicates stored data input, Adrs indicates an address, and a write enable signal, a read enable signal, and a chip select signal (not shown). Yes, and is controlled appropriately. The data output is via a data bus (not shown) of the CPU.
And data in the memory 802 can be accessed by the CPU.

An addition / averaging circuit 803 performs an averaging process by adding the input image data and the output data of the memory 802. The address counter 804 is a counter that generates an address of the memory 802, and the clock for the counting operation is the same signal as the synchronous clock of the input image. The address signal generated here stores the image data in the memory 80.
2 and when reading data from the memory 802 to perform shading correction when reading an image.

The selector 805 switches the address signal supplied to the memory 802. At the time of image processing, the select signal “CPAC” is set to “0” and the output of the address counter 804 is supplied to the Adrs terminal of the memory 802. At the time of access from the CPU, the CPAC signal is set to “1”.
A CA signal which is an address signal of the CPU
02 to the Adrs terminal.

Next, the operation of the shading correction unit 403 of the digital copying machine shown in FIG. 20 will be described for each of (1) when reading the data of the reference white plate and (2) when reading the original image. .

(1) At the time of reading the data of the reference white plate (the position of the exposure lamp is set at the position of the reference white plate) First line: The input image when the exposure lamp is at the position of the reference white plate is stored in the memory 802.

Second line: input image data and memory 80
2 is added to the image data of the first line, and the result is stored in the memory 802 again.

Third line: input image data and memory 80
2 and the result of addition of the image data of the first line and the image data of the second line is stored in the memory 802 again. Hereinafter, the same operation is repeated up to the eighth line.

Ninth line: The addition results of the image data of the first to eighth lines stored in the memory 802 are added.
The average is divided by 8 and averaged by an averaging circuit 803. In the above operation, the address of the memory 802 uses the signal generated by the address counter 804 (selector 80).
5 is set to "0").

(2) At the time of reading a document image The shading correction calculation circuit 801 calculates an input image and data output from the memory 802. The result of this calculation is an image output subjected to shading correction. During this operation, the address of the memory 802 is also stored in the address counter 8
04 (CPAC =
“0”).

Next, a method of detecting a stain on a reference white plate in the digital copying machine according to the embodiment of the present invention configured as described above will be described with reference to the flowcharts of FIGS. 21 and 22.

21 and 22, first, in step S1, the data of the reference white plate (standard white plate) 260 arranged on the non-image portion of the original placing glass 200 of the digital copying machine in the procedure of (1) above. Read. Step S
In step 2, the CPAC signal (select signal) is set to "1", so that the memory 802 can be accessed by the CPU. In step S3, the data of the reference white board 260 stored in the memory 802 is moved to a data buffer (not shown) via the CPU. In step S4, it is determined whether or not the above processing has been completed for all pixels. When this process is completed for all pixels, in step S5, CPAC =
Set to “0” to prohibit CPU access to the memory 802.

Next, in step S6, the exposure lamp 201 of the digital copying machine is advanced from the reference white plate 260 to the image side of the original, and is set at the position of the leading end of the image.
The data at the leading end of the image is read in the same procedure as in step S1. In step S7, CPAC = "1",
The CPU access of the memory 802 is permitted. Step S
In step 8, the data of the reference whiteboard 260 stored in the data buffer in step S3 is compared with the data of the leading end of the image stored in the memory 802 for each pixel, and the difference is calculated.

Next, in step S9, the above step S
The data calculated in step 8 is stored in another data buffer (not shown)
To be stored. In step S10, it is determined whether or not processing for all pixels has been completed. When the processing for all pixels is completed, in step S11, the difference between the data of the reference white plate 260 stored in the data buffer and the image data of the leading end of the document is verified. Here, step S11
Will be described with reference to FIGS.

In the graphs shown in FIGS. 23 to 25, the horizontal axis represents pixels, and the vertical axis represents the difference between the image data of the reference white plate 260 and the image data of the leading edge of the document. In many cases, there is no image at the leading end portion of the document image and the density is constant, so if the reference white plate 260 is not partially stained, it should ideally look like the broken line shown in FIG. However, since the density of the original image slightly varies even at the leading end thereof, the original image has a slight amplitude as shown in FIG. When the partial stain on the reference white plate 260 becomes large, the difference in data is greatly increased only in the dirty portion as shown by P1 in FIG. Therefore, in step S11 in FIG. 22, the difference data in the data buffer are compared with each other, and if the difference is only partially large, it can be detected that the reference white plate 260 is dirty.

Referring again to FIG. 22, in step S12, the result of verification of the comparison value is determined. If the verification result of the comparison value is NG, in step S13, a warning message indicating that the reference white plate is dirty is displayed on the display unit. In this case, as the display means, for example, the touch panel 307 of the operation unit shown in FIG. 5 is used. On the other hand, if the comparison value verification result is OK,
In step S14, the process proceeds to the next operation, for example, a copy operation.

In the above-described embodiment of the present invention, a warning message is issued when the verification result is NG once. However, some image is included in the leading end of the original image. In some cases. Therefore, in order to prevent an erroneous warning from being issued in such a case, the number of times the verification result becomes NG is counted and the number of times N is equal to or greater than a predetermined number.
A warning is issued for the first time when G is reached, or a difference data is stored a plurality of times, and a warning is issued when a portion where the difference data is large is near the same pixel every time. Then, the reference white plate 26 can be obtained more accurately.
It becomes possible to detect a partial stain of zero.

Further, in the above-described embodiment of the present invention, when the reference white plate 260 is soiled, a case is described in which a control is performed to display and output a warning message indicating the fact from the display means. The method of outputting a warning indicating that the reference white plate 260 is dirty is not limited to the display output from the display means, and as described with reference to FIG.
For example, it is also possible to output a warning sound by voice from the voice output means, or to print out a warning message from the print output means.

As described above, according to the embodiment of the present invention, the digital copying machine reads the image from the original 9 line by line, and the optical system and the reading unit 1 for the read image data. Correction means 2 for correcting variations in output values between pixels based on read data of reference white plate 8
A reference white plate data storage unit 3 for storing read data of the reference white plate 8 for all pixels, a document data storage unit 4 for storing read data of an end portion of the document 9 for all pixels, a reference white plate data storage unit 3, Determining means 5 for comparing both data stored in the document data storage means 4 for each pixel and determining that the reference white board 8 is dirty when there is a pixel whose difference between the two data exceeds a predetermined value; Since it has the warning control means 6 for outputting a warning indicating that 8 is dirty and the warning means 7 for outputting a warning, the following effects are obtained.

Normally, attention is paid to the point that there is often no image at the end of the document, that is, the point that the density is often uniform.
The data read from the reference whiteboard stored in the reference whiteboard data storage means 3 is compared with the data read from the document end stored in the document data storage means 4 for each pixel, and the difference between the two data exceeds a predetermined value. If the reference white plate is partially stained for some reason, it is possible to judge that the reference white plate is dirty when there is a pixel, and to issue a warning if there is stain. And
It is possible to warn the user that the reference white plate is dirty and to prompt the user to clean or replace the reference white plate, and as a result, it is possible to prevent an abnormality in the shading correction processing due to partial contamination of the reference white plate, Thus, generation of a defective image can be prevented.

Note that the present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. A storage medium storing software program codes for realizing the functions of the above-described embodiments is supplied to a system or an apparatus, and a computer (or CPU or MPU) of the system or the apparatus executes the program code stored in the storage medium. Needless to say, this can also be achieved by executing the reading.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

Examples of the storage medium for supplying the program code include a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, and CD.
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS or the like running on the computer is actually executed based on the instructions of the program code. It goes without saying that a part or all of the above-described processing is performed, and the functions of the above-described embodiments are realized by the processing.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instruction of the program code, It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0127]

As described above, according to the first aspect of the present invention, there is provided an image processing apparatus having a function of correcting image data based on data read from a reference white plate, wherein the reading means reads an image from a document. Correction means for correcting the read image data based on the read data of the reference white board,
Determining means for determining the presence or absence of dirt on the reference white plate based on a comparison between the read data of the reference white plate and read data of the document, and a warning control unit for issuing a warning when it is determined that the reference white plate is dirty Therefore, the following effects can be obtained. In an image processing apparatus that performs image data correction based on the read data of the reference white board, whether or not the reference white board is dirty is determined based on a comparison between the read data of the reference white board and the read data of the document edge. By issuing a warning, it is possible to detect when the reference white plate is partially contaminated for some reason, and to warn the user that the reference white plate is dirty, and to clean or replace the reference white plate. As a result, it is possible to prevent the shading correction process from being abnormal due to partial contamination of the reference white plate, thereby preventing the generation of a defective image.

According to the second aspect of the present invention, the image processing apparatus has a conversion unit for converting image data obtained by reading the original line by line by the reading unit to digital image data, and the correction unit Since the variation of the output value between the pixels of the reading means in the converted image data is digitally corrected based on the read data of the reference white board, the following effects are obtained. In an image processing apparatus that digitally corrects variations in output values between pixels of an optical system and a reading unit based on read data of a reference white plate, when the reference white plate is partially contaminated for some reason as described above. Can be detected, and it is possible to warn the user that the reference white board is dirty and to prompt the user to clean or replace the reference white board. As a result, the shading correction process due to the partial contamination of the reference white board is possible. Can be prevented, thereby making it possible to prevent a defective image from being generated.

According to the third aspect of the present invention, the image processing apparatus comprises: a reference white plate data storage means for storing the read data of the reference white plate for all pixels; and a document data for storing the read data of the document end portion for all pixels. A storage unit, wherein the determination unit compares both data in the two storage units for each pixel, and when there is a pixel in which the difference between the two data exceeds a predetermined value, the reference white board is dirty. And the warning control means:
Since a warning is issued based on the determination, the following effects are obtained. Normally, there is often no image at the end of the document,
That is, paying attention to the fact that the density is often uniform, the read data of the reference white plate stored in the reference white plate data storage means,
The read data of the document end stored in the document data storage means is compared with each pixel, and if there is a pixel whose difference between the two data exceeds a predetermined value, it is determined that the reference white board is dirty, By performing a control that issues a warning indicating that the white board is dirty, it is possible to detect when the reference white board is partially soiled for some reason, and to warn the user that the reference white board is dirty. As a result, it is possible to prompt the cleaning or replacement of the reference white plate, and as a result, it is possible to prevent the shading correction processing from being abnormal due to the partial contamination of the reference white plate, thereby preventing a defective image from being generated. Can be prevented.

According to a fourth aspect of the present invention, there is provided an image processing apparatus, comprising: a reference white plate data storage means for storing read data of the reference white plate for all pixels; Storage means, and wherein the determination means determines that the reference white plate is soiled when the number of times the number of pixels in which the difference between the two data in the two storage means exceeds a predetermined value is equal to or greater than a predetermined number. Determining, the warning control means:
Since a warning is issued based on the determination, the following effects are obtained. Normally, there is often no image at the end of the document,
That is, paying attention to the fact that the density is often uniform, the read data of the reference white plate stored in the reference white plate data storage means,
The read data of the document end stored in the document data storage means is compared with each pixel for each pixel, and when the number of times the number of pixels having a difference between the two data exceeds a predetermined value exceeds the predetermined number, the reference white board is By performing control to determine that the reference white board is dirty and to issue a warning indicating that the reference white board is dirty, it is possible to more accurately detect when the reference white board is partially soiled for some reason. In addition, it is possible to warn the user that the reference white plate is dirty and to prompt the user to clean or replace the reference white plate. As a result, it is possible to prevent abnormalities in the shading correction process due to partial contamination of the reference white plate. Thereby, generation of a defective image can be prevented.

According to a fifth aspect of the present invention, there is provided an image processing apparatus comprising: a reference white plate data storage means for storing read data of the reference white plate for all pixels; and a document data for storing read data of a document end portion for all pixels. Storage means, wherein the determination means stores the difference between the two data in the two storage means for a plurality of times and when the location where the difference is large is near the same pixel each time, the reference white board is Since it is determined that it is dirty and the warning control means issues a warning based on the determination, the following effects are obtained. Normally, attention is paid to the point that there is often no image at the end of the document, that is, the point that the density is uniform, and the read data of the reference white plate stored in the reference white plate data storage unit and the document data storage unit And the difference between the two data is stored for a plurality of times, and when the place where the difference is large is near the same pixel each time, the reference white board is By performing control to determine that the reference white plate is dirty and to issue a warning indicating that the reference white plate is dirty, it is possible to more accurately detect when the reference white plate is partially soiled for some reason. In addition, it is possible to warn the user that the reference white plate is dirty and to prompt the user to clean or replace the reference white plate. As a result, it is possible to prevent abnormalities in the shading correction process due to partial contamination of the reference white plate. This Accordingly, it is possible to prevent the defective image is generated.

According to the sixth aspect of the present invention, the warning control means of the image processing apparatus causes the warning means to output a warning indicating that the reference white plate is dirty, and thus has the following effects. The warning means warns the user that the reference white plate has been partially stained for some reason, and prompts the user to clean or replace the reference white plate, thereby preventing an abnormality in the shading correction process due to partial contamination of the reference white plate. Can be
Thus, generation of a defective image can be prevented.

According to the seventh aspect of the present invention, since the warning means of the image processing apparatus is a display means for displaying and outputting a warning indicating that the reference white plate is dirty, the following effects are obtained. The display unit warns the user that the reference white plate is partially soiled for some reason, and prompts the user to clean or replace the reference white plate, thereby preventing an abnormality in the shading correction process due to partial contamination of the reference white plate. Can be
Thus, generation of a defective image can be prevented.

According to the eighth aspect of the present invention, since the warning means of the image processing apparatus is a sound output means for outputting a warning indicating that the reference white plate is dirty, the following effects are obtained. . The sound output means warns the user that the reference white plate has been partially stained for some reason, and prompts the user to clean or replace the reference white plate, so that abnormalities in the shading correction process due to partial contamination of the reference white plate can be detected. Thus, generation of a defective image can be prevented.

According to the ninth aspect of the present invention, since the warning means of the image processing apparatus is a print output means for printing and outputting a warning indicating that the reference white board is dirty, the following effects are obtained. . The print output unit warns the user that the reference white plate has been partially stained for some reason, and prompts the user to clean or replace the reference white plate. Thus, generation of a defective image can be prevented.

According to the tenth aspect, since the image processing apparatus has the copy function, the following effects can be obtained. In the image processing apparatus having the copy function, similarly to the above, it is possible to detect when the reference white board is partially soiled for some reason, and warn the user that the reference white board is dirty. It is possible to prompt the cleaning or replacement of the reference white plate, and as a result, it is possible to prevent the shading correction process from being abnormal due to the partial contamination of the reference white plate, thereby preventing a defective image from being generated at the time of copying. Can be prevented.

According to the eleventh aspect, since the image processing apparatus has the printer function, the following effects can be obtained. In the image processing apparatus having the printer function, similarly to the above, it is possible to detect when the reference white board is partially soiled for some reason, and warn the user that the reference white board is dirty. It is possible to prompt the cleaning or replacement of the reference white plate, and as a result, it is possible to prevent the shading correction processing from being abnormal due to the partial contamination of the reference white plate, thereby preventing a defective image from being generated during printing. Can be prevented.

According to the twelfth aspect of the present invention, since the image processing apparatus has the facsimile function, the following effects can be obtained. In the image processing apparatus having the facsimile function, similarly to the above, it is possible to detect when the reference white plate is partially stained for some reason, and warn the user that the reference white plate is dirty. It is possible to prompt the cleaning or replacement of the reference white plate, and as a result, it is possible to prevent the shading correction processing from being abnormal due to the partial contamination of the reference white plate, thereby generating a defective image during facsimile communication. Can be prevented.

According to the thirteenth aspect of the present invention, there is provided a reference white board stain determining method for an image processing apparatus having a function of correcting image data based on data read from a reference white board, comprising: a reading step of reading an image from a document; A correction step of correcting the read image data based on the read data of the reference white board, and a determination step of determining whether or not the reference white board is dirty based on a comparison between the read data of the reference white board and the read data of the document; Since it has a warning control step of giving a warning when it is determined that the reference white plate is dirty, the following effects are obtained. In an image processing apparatus that performs image data correction based on the read data of the reference white plate, the presence or absence of contamination of the reference white plate is determined based on a comparison between the read data of the reference white plate and the read data of the end of the document,
By performing a control to issue a warning when there is dirt, it is possible to detect when the reference white plate is partially soiled for some reason, and to warn the user that the reference white plate is dirty and warn the user. It is possible to prompt the cleaning or replacement of the white plate, and as a result, it is possible to prevent the shading correction process from being abnormal due to the partial contamination of the reference white plate, thereby preventing a defective image from being generated. Can be.

According to a fourteenth aspect of the present invention, the reference white board stain determining method in the image processing apparatus includes a conversion step of converting image data obtained by reading the original line by line in the reading step into digital image data. The correcting step digitally corrects the output value variation between the pixels in the reading step based on the read data of the reference white board with respect to the converted image data, and thus has the following effects. In an image processing apparatus that digitally corrects variations in output values between pixels of an optical system and a reading unit based on read data of a reference white plate, when the reference white plate is partially contaminated for some reason as described above. Can be detected, and it is possible to warn the user that the reference white board is dirty and to prompt the user to clean or replace the reference white board. As a result, the shading correction process due to the partial contamination of the reference white board is possible. Can be prevented, thereby making it possible to prevent a defective image from being generated.

According to a fifteenth aspect of the present invention, the reference white board stain determining method in the image processing apparatus includes: a reference white board data storing step of storing read data of the reference white board for all pixels; A document data storing step of storing pixels, and in the determining step, comparing both the data stored in the both storing steps for each pixel, and if there is a pixel whose difference between the two data exceeds a predetermined value Then, it is determined that the reference white plate is dirty, and in the warning control step, a warning is issued based on the determination. Normally, attention is paid to the point that there is often no image at the end of the document, that is, the point that the density is uniform, and the read data of the reference white plate stored in the reference white plate data storage unit and the document data storage unit Is compared with the read data of the end of the document stored for each pixel, and if there is a pixel whose difference between the two data exceeds a predetermined value, it is determined that the reference white board is dirty, and the reference white board is stained. By performing a control that issues a warning indicating that the reference white plate has been partially contaminated for some reason,
It is possible to warn the user that the reference white plate has become dirty and to prompt the user to clean or replace the reference white plate, and as a result, it is possible to prevent abnormalities in the shading correction processing due to partial contamination of the reference white plate, Thus, generation of a defective image can be prevented.

According to a sixteenth aspect of the present invention, the reference white board stain determining method in the image processing apparatus includes: a reference white board data storing step of storing read data of the reference white board for all pixels; Document data storing step for storing pixels, and in the determining step, when the number of times the number of pixels in which the difference between the two data stored in the both storing steps exceeds a predetermined value is equal to or more than a predetermined number of times, It is determined that the reference white plate is dirty, and in the warning control step, a warning is issued based on the determination. Normally, attention is paid to the point that there is often no image at the end of the document, that is, the point that the density is uniform, and the read data of the reference white plate stored in the reference white plate data storage unit and the document data storage unit Is compared with the read data of the document edge stored in each pixel, and when the number of times that the difference between the two data exceeds a predetermined value is greater than or equal to a predetermined number of times, the reference white board is considered to be dirty. By making a determination and performing a control for issuing a warning indicating that the reference white plate is dirty, it is possible to more accurately detect when the reference white plate is partially soiled for some reason, It is possible to warn the user of the contamination and to prompt the user to clean or replace the reference white plate, and as a result, it is possible to prevent abnormalities in the shading correction process due to partial contamination of the reference white plate, and thereby, Bad image It can be prevented from being generated.

According to the seventeenth aspect of the present invention, the reference white board stain determining method in the image processing apparatus includes: a reference white board data storing step of storing the read data of the reference white board for all pixels; A document data storing step of storing pixels, wherein in the determining step, a difference between the two data stored in the both storing steps is stored a plurality of times, and a portion where the difference is large is in the vicinity of the same pixel each time. In the case of, it is determined that the reference white plate is dirty, and in the warning control step, a warning is issued based on the determination, so that the following effects are obtained. Normally, attention is paid to the point that there is often no image at the end of the document, that is, the point that the density is uniform, and the read data of the reference white plate stored in the reference white plate data storage unit and the document data storage unit And the difference between the two data is stored for a plurality of times, and when the place where the difference is large is near the same pixel each time, the reference white board is By performing control to determine that the reference white board is dirty and to issue a warning indicating that the reference white board is dirty, it is possible to more accurately detect when the reference white board is partially soiled for some reason. In addition, it is possible to warn the user that the reference white plate is dirty and to prompt the user to clean or replace the reference white plate. As a result, it is possible to prevent abnormalities in the shading correction process due to partial contamination of the reference white plate. , The Le, it is possible to prevent the defective image is generated.

According to the eighteenth aspect of the present invention, in the warning control step of the reference white board contamination determining method in the image processing apparatus, a warning indicating that the reference white board is dirty is output from the warning step. Effect.
In the above-mentioned warning step, the user is warned that the reference white plate is partially stained for some reason, and the cleaning or replacement of the reference white plate is encouraged, thereby preventing an abnormality in the shading correction process due to the partial contamination of the reference white plate. Accordingly, generation of a defective image can be prevented.

According to the nineteenth aspect of the present invention, the warning step of the reference white board stain determining method in the image processing apparatus comprises the following steps:
Since this is a display step of displaying and outputting a warning indicating that the reference white plate is dirty, the following effects are obtained. In the above-mentioned display step, the user is warned that the reference white plate is partially stained for some reason, and the user is prompted to clean or replace the reference white plate, thereby preventing an abnormality of the shading correction process due to partial contamination of the reference white plate. Accordingly, generation of a defective image can be prevented.

According to the twentieth aspect of the present invention, the warning step of the reference white board stain determining method in the image processing apparatus comprises the following steps:
Since this is a sound output step of outputting a warning indicating that the reference white plate is dirty, the following effects are obtained. In the audio output step, the user is warned that the reference white plate has been partially stained for some reason, and the cleaning or replacement of the reference white plate is encouraged. Thus, generation of a defective image can be prevented.

According to the twenty-first aspect of the present invention, the warning step of the reference white board stain determining method in the image processing apparatus comprises the following steps:
Since this is a print output step of printing and outputting a warning indicating that the reference white plate is dirty, the following effects are obtained. In the print output step, the user is warned that the reference white plate is partially soiled for some reason, and the user is prompted to clean or replace the reference white plate. Thus, generation of a defective image can be prevented.

According to the twenty-second aspect of the present invention, the reference whiteboard stain determination method in the image processing apparatus is applicable to an image processing apparatus having a copy function, and has the following effects. In the image processing apparatus having the copy function, similarly to the above, it is possible to detect when the reference white board is partially soiled for some reason, and warn the user that the reference white board is dirty. It is possible to prompt the cleaning or replacement of the reference white plate, and as a result, it is possible to prevent the shading correction process from being abnormal due to the partial contamination of the reference white plate, thereby preventing a defective image from being generated at the time of copying. Can be prevented.

According to the twenty-third aspect of the present invention, the reference whiteboard stain determination method in the image processing apparatus is applicable to an image processing apparatus having a printer function, and has the following effects. In the image processing apparatus having the printer function, similarly to the above, it is possible to detect when the reference white board is partially soiled for some reason, and warn the user that the reference white board is dirty. It is possible to prompt the cleaning or replacement of the reference white plate, and as a result, it is possible to prevent the shading correction processing from being abnormal due to the partial contamination of the reference white plate, thereby preventing a defective image from being generated during printing. Can be prevented.

According to the twenty-fourth aspect of the present invention, the reference whiteboard stain determination method in the image processing apparatus is applicable to an image processing apparatus having a facsimile function, and has the following effects. In an image processing apparatus having a facsimile function, similarly to the above, it becomes possible to detect when the reference white plate is partially soiled for some reason,
It is possible to warn the user that the reference white plate is dirty and to prompt the user to clean or replace the reference white plate. As a result,
It is possible to prevent abnormalities in the shading correction processing due to partial contamination of the reference white plate, thereby preventing a defective image from being generated during facsimile communication.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a configuration of a main part of a digital copying machine according to an embodiment of the present invention and corresponding to the claims.

FIG. 2 is an explanatory diagram showing an internal structure of the digital copying machine according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a transfer sheet on an intermediate tray of the digital copying machine according to the embodiment of the present invention.

FIG. 4 is a sectional view showing an internal structure of the automatic document feeder of the digital copying machine according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a key arrangement of an operation unit of the digital copying machine according to the embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a signal processing system of the digital copying machine according to the embodiment of the present invention.

FIG. 7 is a block diagram showing a detailed configuration of an A / D converter of a signal processing system of the digital copying machine according to the embodiment of the present invention.

FIG. 8 is an explanatory diagram showing the operation of the AE circuit in the A / D converter of the signal processing system of the digital copying machine according to the embodiment of the present invention, wherein (a) shows a state in which the reference voltage output is lowered. FIG. 7B is an explanatory diagram illustrating a state where the reference voltage output is increased.

FIG. 9 is an explanatory diagram showing a filter matrix according to the embodiment of the present invention.

FIGS. 10A and 10B are explanatory diagrams illustrating an example of an image combining process according to the embodiment of the present invention; FIG. 10A is an explanatory diagram illustrating an example of an image; FIG. 10B is an explanatory diagram illustrating an example of an image; (c) is an explanatory diagram showing an example of a pattern, (d) is an explanatory diagram showing an example of an image in which a rectangular area around the image of (b) is extracted and fitted into the image of (a), and (e) is a multiplexed image. Explanatory drawing showing an example of an image by synthesis, (f) is an explanatory diagram showing an example of an image having a watermark effect, (g) is a circle with a high density of the image of (a), and (c)
It is explanatory drawing which shows the example replaced by the pattern of FIG.

FIG. 11 is a timing chart showing types of PWM modulation according to the embodiment of the present invention.

FIG. 12 is a timing chart showing types of PWM modulation according to the embodiment of the present invention.

FIG. 13 is a timing chart showing types of PWM modulation according to the embodiment of the present invention.

FIG. 14 is a timing chart showing types of PWM modulation according to the embodiment of the present invention.

FIG. 15 is a timing chart showing types of PWM modulation according to the embodiment of the present invention.

FIG. 16 is a block diagram showing a configuration of a system in which a facsimile function, a printer function, and an electronic sorter function are added to the basic copy function of the digital copying machine according to the embodiment of the present invention.

FIG. 17 is a block diagram showing a configuration of a system in which a facsimile function is added to a basic copy function of the digital copying machine according to the embodiment of the present invention.

FIG. 18 is a block diagram showing a detailed configuration of a resolution / gradation number conversion unit in a system in which a facsimile function, a printer function, and an electronic sorter function are added to the basic copy function of the digital copying machine according to the embodiment of the present invention. is there.

FIG. 19 shows a facsimile in a system in which a facsimile function, a printer function, and an electronic sorter function (or a facsimile function is added to the basic copy function) to the digital copy machine according to the embodiment of the present invention. FIG. 3 is a block diagram illustrating a detailed configuration of a unit.

FIG. 20 is a block diagram showing a schematic configuration inside a shading correction unit in a signal processing system of the digital copying machine according to the embodiment of the present invention.

FIG. 21 is a flowchart showing a process for detecting a reference white plate stain in the digital copying machine according to the embodiment of the present invention.

FIG. 22 is a flowchart showing a process for detecting a stain on a reference white plate in the digital copying machine according to the embodiment of the present invention.

FIG. 23 is an explanatory diagram showing a method for detecting contamination of a reference white plate in the digital copying machine according to an embodiment of the present invention.

FIG. 24 is an explanatory diagram showing a method for detecting contamination of a reference white plate in the digital copying machine according to the embodiment of the present invention.

FIG. 25 is an explanatory diagram showing a method for detecting contamination of a reference white plate in the digital copying machine according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reading means 2 Correction means 3 Reference white board data storage means 4 Original data storage means 5 Judgment means 6 Warning control means 7 Warning means 8, 260 Reference white board 201 Exposure lamp 307 Touch panel 401 CCD line sensor 402 A / D conversion unit 403 Shading correction Unit 423 CPU 802 memory

Claims (24)

[Claims] 1. An image processing apparatus having a function of correcting image data based on data read from a reference white board, comprising: a reading unit for reading an image from a document; and reading the read image data based on the read data of the reference white board. Correction means for correcting, reference means for determining the presence or absence of dirt on the reference white board based on a comparison between the read data of the reference white board and read data of the document, and a warning when the reference white board is determined to be dirty An image processing apparatus comprising: a warning control unit that performs the following. 2. The image processing apparatus according to claim 1, further comprising a conversion unit configured to convert image data obtained by reading the original line by line with the reading unit into digital image data, wherein the correction unit converts the converted image data into pixels of the reading unit. 2. The image processing apparatus according to claim 1, wherein a variation in output value is digitally corrected based on read data of the reference white plate. 3. A reference white plate data storage unit for storing read data of the reference white plate for all pixels, and a document data storage unit for storing read data of a document end portion for all pixels, wherein the determination unit includes: The two data in the two storage means are compared for each pixel, and when there is a pixel in which the difference between the two data exceeds a predetermined value, the reference white board is determined to be dirty, and the warning control means performs the determination. The image processing apparatus according to claim 1, wherein a warning is issued based on: 4. A reference white plate data storage unit for storing read data of the reference white plate for all pixels, and a document data storage unit for storing read data of a document edge for all pixels, wherein the determination unit includes When the number of times that there is a pixel in which the difference between the two data in the two storage units exceeds a predetermined value is equal to or more than a predetermined number, the reference white board is determined to be dirty, and the warning control unit determines whether the determination is made. 3. The image processing apparatus according to claim 1, wherein a warning is issued based on the warning. 5. A reference white board data storage unit for storing read data of the reference white board for all pixels, and a document data storage unit for storing read data of a document end portion for all pixels, wherein the determination unit comprises: When the difference between the two data in the two storage units is stored a plurality of times and the place where the difference is large is near the same pixel each time, it is determined that the reference white board is dirty, and the warning control unit is 3. The image processing apparatus according to claim 1, wherein a warning is issued based on the determination. 6. The image processing apparatus according to claim 1, wherein the warning control unit outputs a warning indicating that the reference white plate is dirty from the warning unit. 7. The image processing apparatus according to claim 6, wherein the warning unit is a display unit that outputs a warning indicating that the reference white plate is dirty. 8. The image processing apparatus according to claim 6, wherein the warning unit is a voice output unit that outputs a warning indicating that the reference white board is dirty. 9. The image processing apparatus according to claim 6, wherein the warning unit is a print output unit that prints out a warning indicating that the reference white board is dirty. 10. The image processing apparatus according to claim 1, further comprising a copy function. 11. The image processing apparatus according to claim 1, wherein the image processing apparatus has a printer function. 12. The image processing apparatus according to claim 1, having a facsimile function. 13. A reference white plate stain determining method in an image processing apparatus having a function of correcting image data based on data read from a reference white plate, comprising: a reading step of reading an image from a document; A correction step of correcting based on the read data of the white board, a determining step of determining whether or not the reference white board is stained based on a comparison between the read data of the reference white board and the read data of the document, and that the reference white board is dirty. A warning control step of issuing a warning when the determination is made, the reference whiteboard stain determination method in the image processing apparatus. 14. A conversion step of converting image data obtained by reading a document line by line in the reading step into digital image data, wherein in the correcting step, the pixel data in the reading step is applied to the converted image data. 14. The reference white board stain determining method in the image processing apparatus according to claim 13, wherein a variation in output value between the two is digitally corrected based on read data of the reference white board. 15. A reference white board data storing step of storing read data of the reference white board for all pixels, and a document data storing step of storing read data of a document end portion for all pixels. The two data stored in the two storage steps are compared for each pixel, and if there is a pixel in which the difference between the two data exceeds a predetermined value, it is determined that the reference white board is dirty, and in the warning control step, The method according to claim 13, wherein a warning is issued based on the determination. 16. A reference white board data storing step of storing read data of the reference white board for all pixels, and a document data storing step of storing read data of a document edge for all pixels, wherein the determination step includes: When the number of times that there is a pixel in which the difference between the two data stored in the two storage steps exceeds a predetermined value is equal to or more than a predetermined number, it is determined that the reference white board is dirty, and in the warning control step, The method according to claim 13 or 14, wherein a warning is issued based on the determination. 17. A reference white board data storing step of storing read data of the reference white board for all pixels, and a document data storing step of storing read data of a document end portion for all pixels. The difference between the two data stored in the two storage steps is stored for a plurality of times, and when the place where the difference is large is near the same pixel each time, it is determined that the reference white board is dirty, and the warning control is performed. The method according to claim 13, wherein in the step, a warning is issued based on the determination. 18. The reference white board in the image processing apparatus according to claim 13, wherein in the warning control step, a warning indicating that the reference white board is dirty is output in the warning step. Dirt determination method. 19. The method according to claim 18, wherein the warning step is a display step of displaying and outputting a warning indicating that the reference white board is dirty. 20. The method according to claim 18, wherein the warning step is a sound output step of outputting a warning indicating that the reference white board is dirty. 21. The method according to claim 18, wherein the warning step is a print output step of printing out a warning indicating that the reference white board is dirty. 22. The method according to claim 13, wherein the method is applicable to an image processing apparatus having a copy function. 23. The method according to claim 13, wherein the method is applicable to an image processing apparatus having a printer function. 24. An image processing apparatus having a facsimile function, which is applicable to an image processing apparatus having a facsimile function.
3. A reference whiteboard stain determination method in the image processing apparatus according to any one of 3.